PPI::HTML is the successor to the now-redundant PPI::Format::HTML.

While early on it was thought that the same formatting code might be
able to be used for a variety of different types of things (ANSI and
HTML for example) later developments with the here-doc code and the need
for independently-written serializers meant that this idea had to be
discarded.

The new module is much cleaner. Simply create an object with the options
you want, pass PPI::Document objects to the "html" method, and you get
strings of HTML that you can do whatever you want with.
